Super color vision

A tetrachromat is a woman who can see four distinct ranges of color, instead of the three that most of us live with. . .

It may be impossible for us trichromats to imagine what a four-color world would look like. But mathematics alone suggests the difference would be astounding, said Jay Neitz, a renowned color vision researcher at the Medical College of Wisconsin.

Each of the three standard color-detecting cones in the retina -- blue, green and red -- can pick up about 100 different gradations of color, Dr. Neitz estimated. But the brain can combine those variations exponentially, he said, so that the average person can distinguish about 1 million different hues.

A true tetrachromat has another type of cone in between the red and green -- somewhere in the orange range -- and its 100 shades theoretically would allow her to see 100 million different colors.

More detail on the underlying physiology and genetics here; this is not a new story, so there is quite a bit of material online for further reading (a selection here and here).

Posted by David on September 18, 2006 10:07 AM